Fix jest test suites (#268)

* CRLF to LF

* add babel-jest

* use ES6 style imports

* fix bugs manifest by test suite

* add babel test config

client/package.json

@@ -59,6 +59,7 @@
     "autoprefixer": "^9.1.1",
     "babel-core": "^6.13.2",
     "babel-eslint": "^8.2.6",
+    "babel-jest": "^23.6.0",
     "babel-loader": "^7.1.2",
     "babel-plugin-istanbul": "^4.1.6",
     "babel-plugin-transform-decorators-legacy": "^1.3.4",
@@ -105,5 +106,17 @@
       "**/__tests__/**/?(*.)(spec|test).js?(x)"
     ],
     "testURL": "http://localhost/"
+  },
+  "babel": {
+    "env": {
+      "test": {
+        "presets": [
+          [
+            "env"
+          ],
+          "react"
+        ]
+      }
+    }
   }
 }